1. Field of the Invention
This invention is in the field of retractors typically used for seat belts.
2. Description of the Prior Art
Many patents have been issued that disclose a variety of automatic retracting devices that include a spring biased spool for withdrawing a webbed belt into the retractor, but yieldable to permit the webbed belt to be withdrawn from the spool for attachment at the opposite end to a buckle or tongue. Typically, the prior art retracting spools include ratchet configured end plates that are lockingly engaged by a spring biased pawl bar pivotally mounted to the retractor housing. The various mechanisms of the retractors, including specifically a clutch plate that is in direct contact with the pawl bar, hold the pawl bar out of the locking position until the retractor is slightly rewound, at which time the clutch plate rotates with the retractor spool and permits the locking pawl bar to pivot and lockingly engage the retractor spool in ratchet and engaging pawl fashion. Once the locking bar is allowed to pivot into the locking position, the retractor is operable to prevent further withdrawal of the webbed belt from the retractor spool, but the retractor spool's ratchet configured end plates and the locking pawl bar remain operable to permit retraction of the webbed belt into the retractor. Thus, if more than the desired amount of webbed belt material is withdrawn from the retractor while attaching the opposite end of the belt to a tongue or buckle, the spool will rewind under the spring bias, applying a snug tension to the webbed belt, and the locking bar will simultaneously lockingly engage the retractor spool, preventing further withdrawal of the webbed belt from the retractor. If the snug tension upon the webbed belt is released to any appreciable degree, the spring bias upon the spool will operate to further withdraw the webbed belt into the retractor, and the ratchet and pawl relationship of the locking bar and retractor spool end plates will operate to lockingly engage the retractor spool after a snug tension has been reestablished, preventing re-withrawal of the webbed belt from the retractor.
It is known to provide the automatic retracting devices described above as restraining devices, or seat belts, in moving vehicles of all types. In seat belt applications of the automatically retracting devices described above wherein the passenger is jolted or bounces in dramatic contrast to the ride experienced in the normal passenger automobile, such as in construction equipment and semitrailer cabs, the snug tension upon the webbed belt experienced when the vehicle is at rest can be repeatedly eased as a result of the passenger's kinetics. With each downward jolt or bounce, the snug tension on the webbed belt can be loosened to such an extent that the spring biased retractor spool operates to withdraw additional webbed belt into the retractor until a snug tension is reestablished while simultaneously the ratchet and pawl relationship of the locking bar and spool end plates operates to prevent the additional webbed material withdrawn into the retractor from being re-withdrawn from the retractor as the passenger rebounds. The result is an uncomfortable tensioning of the webbed belt. The passenger must either remove the seat belt completely and resecure it upon each such occurrence, or the passenger must suffer continuing discomfort.
Disclosed herein is a belt locking mechanism for counterbalancing the spring bias of such an automatic retractor spool to deactivate the retractor spool's normal withdrawal mechanisms after the opposite end of the webbed belt has been attached to a tongue or buckle and has been snuggly tensioned, and the locking bar has lockingly engaged the retractor spool. Also disclosed is an integral pushrod mechanism operable to rotate the cam plate to the extent necessary to allow the pawl bar to lockingly engage the retractor spool simultaneously with the engagement of the belt locking mechanism. Absent such a pushrod mechanism, it might be possible for the webbed belt to be forcibly withdrawn even though the belt locking mechanism is engaged with the belt. The retractor spool is thus prevented from withdrawing even to the slight degree necessary to rotate the cam plate to permit the retractor pawl to lockingly engage the retractor spool.
It is also known to provide automatic retracting devices for such use encased in plastic boots. The new and improved retracting device disclosed herein is described in combination with such an automatic restraining device with seat belt encased in such a plastic boot.